The present invention relates to a changeover device for controlling dosing frames used in connection with a series of sole or bottom flues in a coke oven, particularly wherein two dosing frames in a valve chamber are each alternately folded between a dosing position in front of the bottom flue openings and a withdrawn position spaced from the bottom flue openings by means of timed angular rotation of pivots of the dosing frames.
Such dosing frames are described in German Pat. No. 974,914. The dosing frames are provided with dosing openings associated with the separate bottom flues and the free cross-section of such dosing openings is adjustable. The dosing openings of the two frames are of different sizes, dependent on the requirements of the particular operation. In regeneratively heated combination or vertical-flue regenerative ovens, one of the two dosing frames is associated with each direction of flow.